Structural Characterization of Homoepitaxial SrTiO₃ Films Grown by Pulsed Laser Deposition

We report the structural characterization of homoepitaxial (001) SrTiO₃ films grown by pulsed laser deposition on single crystal (001) SrTiO₃ substrates. X-ray diffraction −2 scan and φ scan were used to study the lattice constants and crystal quality of the SrTiO₃ films. Lattice expansion in the c-axis from the bulk SrTiO₃ was found in many films, which is related to the off-stoichiometry in the films. We create a contour map for both the lattice expansion and cation composition as functions of laser energy density and oxygen pressure, which shows a broad range of growth conditions to achieve stoichiometry in SrTiO₃ films.